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author | Jason Zaugg <jzaugg@gmail.com> | 2015-07-30 15:41:12 +1000 |
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committer | Jason Zaugg <jzaugg@gmail.com> | 2015-07-30 15:41:12 +1000 |
commit | 5ee834d4fce81e25cfcc3ae770e3f1583d82d658 (patch) | |
tree | 7bfedd4f30b05bdba8905e83a87b2c6d926e3e5f | |
parent | a7a1e5b5e93724d7195ced9168f17e43438bff66 (diff) | |
parent | 7238bc1982cb1d87157c650115a2ae92a58430c9 (diff) | |
download | scala-async-5ee834d4fce81e25cfcc3ae770e3f1583d82d658.tar.gz scala-async-5ee834d4fce81e25cfcc3ae770e3f1583d82d658.tar.bz2 scala-async-5ee834d4fce81e25cfcc3ae770e3f1583d82d658.zip |
Merge pull request #132 from retronym/ticket/105
Avoid dead code warnings for users of async.
-rw-r--r-- | src/main/scala/scala/async/Async.scala | 2 | ||||
-rw-r--r-- | src/main/scala/scala/async/internal/AsyncId.scala | 2 | ||||
-rw-r--r-- | src/main/scala/scala/async/internal/AsyncTransform.scala | 11 | ||||
-rw-r--r-- | src/main/scala/scala/async/internal/ExprBuilder.scala | 57 | ||||
-rw-r--r-- | src/test/scala/scala/async/package.scala | 12 | ||||
-rw-r--r-- | src/test/scala/scala/async/run/WarningsSpec.scala | 48 |
6 files changed, 108 insertions, 24 deletions
diff --git a/src/main/scala/scala/async/Async.scala b/src/main/scala/scala/async/Async.scala index bacf70a..0bba6ed 100644 --- a/src/main/scala/scala/async/Async.scala +++ b/src/main/scala/scala/async/Async.scala @@ -42,7 +42,7 @@ object Async { * Run the block of code `body` asynchronously. `body` may contain calls to `await` when the results of * a `Future` are needed; this is translated into non-blocking code. */ - def async[T](body: T)(implicit execContext: ExecutionContext): Future[T] = macro internal.ScalaConcurrentAsync.asyncImpl[T] + def async[T](body: => T)(implicit execContext: ExecutionContext): Future[T] = macro internal.ScalaConcurrentAsync.asyncImpl[T] /** * Non-blocking await the on result of `awaitable`. This may only be used directly within an enclosing `async` block. diff --git a/src/main/scala/scala/async/internal/AsyncId.scala b/src/main/scala/scala/async/internal/AsyncId.scala index 6b4dbce..3afa55b 100644 --- a/src/main/scala/scala/async/internal/AsyncId.scala +++ b/src/main/scala/scala/async/internal/AsyncId.scala @@ -12,7 +12,7 @@ object AsyncId extends AsyncBase { lazy val futureSystem = IdentityFutureSystem type FS = IdentityFutureSystem.type - def async[T](body: T) = macro asyncIdImpl[T] + def async[T](body: => T) = macro asyncIdImpl[T] def asyncIdImpl[T: c.WeakTypeTag](c: Context)(body: c.Expr[T]): c.Expr[T] = asyncImpl[T](c)(body)(c.literalUnit) } diff --git a/src/main/scala/scala/async/internal/AsyncTransform.scala b/src/main/scala/scala/async/internal/AsyncTransform.scala index ec3a2a1..baa3fc2 100644 --- a/src/main/scala/scala/async/internal/AsyncTransform.scala +++ b/src/main/scala/scala/async/internal/AsyncTransform.scala @@ -70,12 +70,11 @@ trait AsyncTransform { for ((state, flds) <- assignsOf) { val assigns = flds.map { fld => val fieldSym = fld.symbol - Block( - List( - asyncBase.nullOut(c.universe)(c.Expr[String](Literal(Constant(fieldSym.name.toString))), c.Expr[Any](Ident(fieldSym))).tree - ), - Assign(gen.mkAttributedStableRef(thisType(fieldSym.owner), fieldSym), mkZero(fieldSym.info)) - ) + val assign = Assign(gen.mkAttributedStableRef(thisType(fieldSym.owner), fieldSym), mkZero(fieldSym.info)) + asyncBase.nullOut(c.universe)(c.Expr[String](Literal(Constant(fieldSym.name.toString))), c.Expr[Any](Ident(fieldSym))).tree match { + case Literal(Constant(value: Unit)) => assign + case x => Block(x :: Nil, assign) + } } val asyncState = asyncBlock.asyncStates.find(_.state == state).get asyncState.stats = assigns ++ asyncState.stats diff --git a/src/main/scala/scala/async/internal/ExprBuilder.scala b/src/main/scala/scala/async/internal/ExprBuilder.scala index 4e521c9..164e85b 100644 --- a/src/main/scala/scala/async/internal/ExprBuilder.scala +++ b/src/main/scala/scala/async/internal/ExprBuilder.scala @@ -34,8 +34,18 @@ trait ExprBuilder { var stats: List[Tree] + def statsAnd(trees: List[Tree]): List[Tree] = { + val body = stats match { + case init :+ last if tpeOf(last) =:= definitions.NothingTpe => + adaptToUnit(init :+ Typed(last, TypeTree(definitions.AnyTpe))) + case _ => + adaptToUnit(stats) + } + Try(body, Nil, adaptToUnit(trees)) :: Nil + } + final def allStats: List[Tree] = this match { - case a: AsyncStateWithAwait => stats :+ a.awaitable.resultValDef + case a: AsyncStateWithAwait => statsAnd(a.awaitable.resultValDef :: Nil) case _ => stats } @@ -52,8 +62,9 @@ trait ExprBuilder { def nextStates: List[Int] = List(nextState) - def mkHandlerCaseForState[T: WeakTypeTag]: CaseDef = - mkHandlerCase(state, stats :+ mkStateTree(nextState, symLookup)) + def mkHandlerCaseForState[T: WeakTypeTag]: CaseDef = { + mkHandlerCase(state, statsAnd(mkStateTree(nextState, symLookup) :: Nil)) + } override val toString: String = s"AsyncState #$state, next = $nextState" @@ -87,10 +98,10 @@ trait ExprBuilder { val tryGetOrCallOnComplete = if (futureSystemOps.continueCompletedFutureOnSameThread) If(futureSystemOps.isCompleted(c.Expr[futureSystem.Fut[_]](awaitable.expr)).tree, - Block(ifIsFailureTree[T](futureSystemOps.getCompleted[Any](c.Expr[futureSystem.Fut[Any]](awaitable.expr)).tree) :: Nil, literalUnit), - Block(callOnComplete :: Nil, Return(literalUnit))) + adaptToUnit(ifIsFailureTree[T](futureSystemOps.getCompleted[Any](c.Expr[futureSystem.Fut[Any]](awaitable.expr)).tree) :: Nil), + Block(toList(callOnComplete), Return(literalUnit))) else - Block(callOnComplete :: Nil, Return(literalUnit)) + Block(toList(callOnComplete), Return(literalUnit)) mkHandlerCase(state, stats ++ List(mkStateTree(onCompleteState, symLookup), tryGetOrCallOnComplete)) } @@ -110,11 +121,11 @@ trait ExprBuilder { */ def ifIsFailureTree[T: WeakTypeTag](tryReference: => Tree) = If(futureSystemOps.tryyIsFailure(c.Expr[futureSystem.Tryy[T]](tryReference)).tree, - Block(futureSystemOps.completeProm[T]( + Block(toList(futureSystemOps.completeProm[T]( c.Expr[futureSystem.Prom[T]](symLookup.memberRef(name.result)), c.Expr[futureSystem.Tryy[T]]( TypeApply(Select(tryReference, newTermName("asInstanceOf")), - List(TypeTree(futureSystemOps.tryType[T]))))).tree :: Nil, + List(TypeTree(futureSystemOps.tryType[T]))))).tree), Return(literalUnit)), Block(List(tryGetTree(tryReference)), mkStateTree(nextState, symLookup)) ) @@ -382,12 +393,12 @@ trait ExprBuilder { val t = c.Expr[Throwable](Ident(name.t)) val complete = futureSystemOps.completeProm[T]( c.Expr[futureSystem.Prom[T]](symLookup.memberRef(name.result)), futureSystemOps.tryyFailure[T](t)).tree - Block(complete :: Nil, Return(literalUnit)) + Block(toList(complete), Return(literalUnit)) })), EmptyTree) def forever(t: Tree): Tree = { val labelName = name.fresh("while$") - LabelDef(labelName, Nil, Block(t :: Nil, Apply(Ident(labelName), Nil))) + LabelDef(labelName, Nil, Block(toList(t), Apply(Ident(labelName), Nil))) } /** @@ -405,7 +416,7 @@ trait ExprBuilder { def onCompleteHandler[T: WeakTypeTag]: Tree = { val onCompletes = initStates.flatMap(_.mkOnCompleteHandler[T]).toList forever { - Block(resumeFunTree :: Nil, literalUnit) + adaptToUnit(toList(resumeFunTree)) } } } @@ -422,12 +433,32 @@ trait ExprBuilder { Assign(symLookup.memberRef(name.state), Literal(Constant(nextState))) private def mkHandlerCase(num: Int, rhs: List[Tree]): CaseDef = - mkHandlerCase(num, Block(rhs, literalUnit)) + mkHandlerCase(num, adaptToUnit(rhs)) + + private def tpeOf(t: Tree): Type = t match { + case _ if t.tpe != null => t.tpe + case Try(body, Nil, _) => tpeOf(body) + case _ => NoType + } + + private def adaptToUnit(rhs: List[Tree]): c.universe.Block = { + rhs match { + case init :+ last if tpeOf(last) <:< definitions.UnitTpe => + Block(init, last) + case _ => + Block(rhs, literalUnit) + } + } private def mkHandlerCase(num: Int, rhs: Tree): CaseDef = CaseDef(Literal(Constant(num)), EmptyTree, rhs) - def literalUnit = Literal(Constant(())) + def literalUnit = Literal(Constant(())) // a def to avoid sharing trees + + def toList(tree: Tree): List[Tree] = tree match { + case Block(stats, Literal(Constant(value))) if value == () => stats + case _ => tree :: Nil + } def literalNull = Literal(Constant(null)) } diff --git a/src/test/scala/scala/async/package.scala b/src/test/scala/scala/async/package.scala index 166edaa..9fbb7df 100644 --- a/src/test/scala/scala/async/package.scala +++ b/src/test/scala/scala/async/package.scala @@ -51,6 +51,18 @@ package object async { m.mkToolBox(options = compileOptions) } + import scala.tools.nsc._, reporters._ + def mkGlobal(compileOptions: String = ""): Global = { + val settings = new Settings() + settings.processArgumentString(compileOptions) + val initClassPath = settings.classpath.value + settings.embeddedDefaults(getClass.getClassLoader) + if (initClassPath == settings.classpath.value) + settings.usejavacp.value = true // not running under SBT, try to use the Java claspath instead + val reporter = new StoreReporter + new Global(settings, reporter) + } + def scalaBinaryVersion: String = { val PreReleasePattern = """.*-(M|RC).*""".r val Pattern = """(\d+\.\d+)\..*""".r diff --git a/src/test/scala/scala/async/run/WarningsSpec.scala b/src/test/scala/scala/async/run/WarningsSpec.scala index 3a7843a..00c6466 100644 --- a/src/test/scala/scala/async/run/WarningsSpec.scala +++ b/src/test/scala/scala/async/run/WarningsSpec.scala @@ -7,10 +7,8 @@ package run import org.junit.Test -import scala.async.internal.AsyncId -import scala.concurrent.Await -import scala.concurrent.duration._ import scala.language.{postfixOps, reflectiveCalls} +import scala.tools.nsc.reporters.StoreReporter class WarningsSpec { @@ -32,4 +30,48 @@ class WarningsSpec { """.stripMargin }) } + + @Test + // https://github.com/scala/async/issues/74 + def noDeadCodeWarningForAsyncThrow() { + val global = mkGlobal("-cp ${toolboxClasspath} -Yrangepos -Ywarn-dead-code -Xfatal-warnings -Ystop-after:refchecks") + // was: "a pure expression does nothing in statement position; you may be omitting necessary parentheses" + val source = + """ + | class Test { + | import scala.async.Async._ + | import scala.concurrent.ExecutionContext.Implicits.global + | async { throw new Error() } + | } + """.stripMargin + val run = new global.Run + val sourceFile = global.newSourceFile(source) + run.compileSources(sourceFile :: Nil) + assert(!global.reporter.hasErrors, global.reporter.asInstanceOf[StoreReporter].infos) + } + + @Test + def noDeadCodeWarningInMacroExpansion() { + val global = mkGlobal("-cp ${toolboxClasspath} -Yrangepos -Ywarn-dead-code -Xfatal-warnings -Ystop-after:refchecks") + val source = """ + | class Test { + | def test = { + | import scala.async.Async._, scala.concurrent._, ExecutionContext.Implicits.global + | async { + | val opt = await(async(Option.empty[String => Future[Unit]])) + | opt match { + | case None => + | throw new RuntimeException("case a") + | case Some(f) => + | await(f("case b")) + | } + | } + | } + |} + """.stripMargin + val run = new global.Run + val sourceFile = global.newSourceFile(source) + run.compileSources(sourceFile :: Nil) + assert(!global.reporter.hasErrors, global.reporter.asInstanceOf[StoreReporter].infos) + } } |